Statements of Income (Unaudited) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Net sales	$ 3,626,177	$ 3,657,978	$ 7,518,535	$ 7,088,846
Costs and expenses:
Cost of sales	1,693,753	1,499,390	3,403,870	2,860,403
Operating expenses	620,229	513,012	1,166,978	970,139
Research and development expense	112,266	130,025	243,932	218,311
Total costs and expenses	2,426,248	2,142,427	4,814,780	4,048,853
Income from operations	1,199,929	1,515,551	2,703,755	3,039,993
Other (expense) income:
Investment income	58,860	45,640	99,410	85,400
Net (loss) gain on marketable securities	(460,278)	137,574	(853,938)	65,527
Total other (expense) income	(401,418)	183,214	(754,528)	150,927
Income before provision for income taxes	798,511	1,698,765	1,949,227	3,190,920
Provision for income taxes	165,187	354,241	404,438	665,194
Net income	$ 633,324	$ 1,344,524	$ 1,544,789	$ 2,525,726
Earnings per common share (basic and diluted) (in dollars per share)	$ 0.14	$ 0.29	$ 0.34	$ 0.55
Weighted average shares (basic and diluted) (in shares)	4,594,319	4,594,319	4,594,319	4,594,319